The various mechanisms by which immunological competence is transmitted from mother to infant represent an important interest area for the development of effective immunity during early life. Since alcohol consumption reportedly has adverse effects on the mother's immune system and on the growth and development of the fetus (fetal alcohol syndrome), it could also alter the important passage of cellular immunity to the baby that may be crucial to its early protection and could also affect the early development of the infant's own immune system. Using established techniques in our laboratories, assessments will be made as to the effects that maternal and neonatal alcohol consumption have on: (1) the normal processes that bring lymphocytes to the mammary gland, (2) changes in the various subpopulations of lymphocytes in the lactating breast, (3) the amount and types of lymphocytes passaged into milk and to the neonate, and (4) alterations in the functional aspects of cellular immunity provided to the neonate during lactation. Assessments will also be made on the effects of alcohol consumption on the normal development of the infant's intestinal lymphoid tissues using pups born to alcoholic mothers or raised artificially from birth on an alcohol diet. The numbers and percentage of various subtypes of lymphocytes in the mammary tissue will be followed using autoradiography (injections of 3H-thymidine for kinetic studies and 3H-uridine labeled syngeneic lymph node cells for cell trafficking studies to the breast). Subpopulations of lymphocytes in the breast and milk will be characterized using highly specific B- and T-cell subset markers and visualized by indirect immunofluorescence and other immunocytochemical techniques. The effects of maternal and neonatal consumption of alcohol on the development and function of the baby's gastrointestinal lymphoid tissue will be assessed by observing the development of Peyer's patches and intestinal villus infiltrations of leukocytes as well as changes in the functional transfer of immunity to the neonate. A thorough understanding of the effects of maternal alcohol consumption on the passage of immunity from mother to child during suckling and the consequences to the development of the baby's own immune system may help to explain the increased risks infants have to diseases during the neonatal period.